In the picture of the ring nebula, M57, above, taken by Todd Gross, a very rudimentary photometry was done on some surrounding stars. Although these figures should be used as an estimate, many agree with Brian Skiff's photometry. I personally have found it impossible to see the ring nebula central star(s) without first glimpsing at least the 14.7/14.9 double star first, and in fact, I look for the 15.6 mag. star listed before I expect to see it on a given night. It takes good transparency, and excellent seeing to do it.